Overview of CLEERS(Diesel Cross-Cut Lean Exhaust

Emissions Reduction Simulation)Program

D.O.E. Crosscut Workshop on Lean Emissions Reduction SimulationMay 7-8, 2001

National Transportation Research CenterKnoxville, TN

Richard J. Blint

GM R & D Center

GOAL

•Issues

­Accessible, reliable component submodels

•Integration of submodels

•Realistic engine out data for Federal Test Proceedure (FTP) driving cycles

Simulate emission control systems under realistic conditions to optimize the engine/aftertreatment integration

Advantages of System Modeling

•Reduced cost and time for system optimization

•Identification of bottlenecks and opportunites

•Improved/tailored component design

–engines

–catalysts

–sensors

–control strategies

•Vehicle test planning

OutlineThe organizationThe “issue”

Integration between aftertreatment and engineApproach-Provide a common ground for industry and “the outside world” to develop the tools for aftertreatment simulation

Develop a center for computational comparisionProvide a baseline modeling environmemtDevelop a “library” of engine out measurements for the testing of simulation componentsGather a library of simulation and experimental results to serve as technical benchmarks for evaluating new component submodels

Technical exchangeWeb based informationTechnical meetings to get the “right” people in the same roomWeb based information exchange on collaborative programs

What we expect from this meetingWrap-up

Sponsorship

Diesel Cross Cut Team(organized by the DOE)

Members

•DaimlerChrylser

•Ford

•GM

•Caterpillar

•Cummins

•DDC

•DOE (OHVT)

CLEERS is coordinated by a subcommittee appointed by the Diesel Cross-Cut Team

CLEERS subcommittee:

•R. Blint, General Motors

•N. Hakim, Detroit Diesel

•G. Singh, U.S.-DOE/HQ

•S. Daw, Oak Ridge National Lab

•C. Rutland, Wisconsin

•H. Kung, Northwestern

Website:

•General information about emissions control simulation

•Technical information and benchmark data base

•Data and model exchange forum

Workshops:

•Focused 2-day meetings on emissions control topics

•Invited and contributed technical presentations on specific topics

•Overview presentations and panel discussions

Simulation Testbed

Time scale: 1s to minutes

DriverSignal

Air Fuel

ElectronicController

Engine

Intake Metering

Sensor/Thermocouple

Catalyst Emissions

Reductant Metering

EGR

Closed Loop Operation

•Engine Control Unit (ECU) controls engine

•ECU responds to aftertreatment requirements

•Aftertreatment “determines” engine response

System Modeling Requirements

• Must be compatible with industry engine modeling systems to enable testing on relevant engine systems

• Allow interchangeable submodels for research and development purposes

• Should be supported and generally available (most likely proprietary)

Key requirements for realistic simulations

• Accurate prediction of engine-out conditions– Variable flow, composition, temperature– Normal operation (cold start, acceleration, load change)– Anomalous operation (misfire, cylinder cut-out)

• Predict component response under engine conditions– Translate reactor measurements to simulation parameters– Correlate/refine reactor response to component engine

response over the range of conditions• Federal Test Procedure (FTP) prediction

– Ultimate standard for the simulation– Evaluate engine control algorithm for effect on catalyst

efficiency

Elements of the System

Intake, Combustion & Emissions Model

Exh. Manifold DOC

Component architecture

Mixing, heat loss and gas phase reactions

Downpipe

Realistic 1 second or better data over the FTP

Engine-Out Data NOx catalystDPF

Integrating SoftwareBasic framework for all simulation

components

EngineArchitecture

Specific engineand flow

component models(Fluent, Star-CD,

Chemkin)

Control Strategies(SIMULINK,

MATLAB)

Aftertreatment component

models(catalysts,

particulate traps,downpipe reactors)

Simulation Framework

•Integrating Software

–MATLAB/SIMULINK

–GT-POWER

–WAVE

–? KIVA, CHAD

Simulation Center (Goals)

• ORNL Home (Stuart Daw, Coordinator)• Central system for evaluating aftertreatment models

with a complete set of aftertreatment model• Suite of baseline models for comparison Library of

benchmark case inputs (e.g., OEM engine out data and catalyst out if possible)

• Library of benchmark case results for public, privatemodels

• Web-based simulation access

Crosscut Aftertreatment Simulation Website

– Downloadable case results, public/private models– Remote job submission to access engine data or

simulation code– Tutorial and education pages– Security controls to limit access according to the

users (e.g., public, crosscut member, proprietary)– Workshop announcements and downloadable

presentations/proceedings – Public forum, bulletin board

Framework Codes•GT-Power

–Full engine simulation suite

–Point and click construction of full powertrain including aftertreatment

–Proprietary simulation environment, but accepts submodels in fortran or C.

–Aftertreatment models can interact with engine simulation

•MATLAB

–Industry standard simulation environment

–Engine simulation codes can be brought in as separate entities

–No feedback from aftertreatment to engine simulation

License Plan• Tentative ORNL License Plan

– GT-Power on UNIX machine with Flexlm license – GT-Power copy on Windows PC with node-locked license– MATLAB generally available– Component models available with individual restrictions– Direct access by crosscut members holding GT Power

and/or MATLAB licenses– Non crosscut members are enabled based on project

• Non-crosscut exploratory• Non-crosscut development• Non-crosscut industrial collaboration

Industrial Strengths for the program

• Product relevant systems modeling• Exhaust measurements from production

engines• Emission engineers• Catalyst suppliers• Customer driven focus

Non Proprietary Needs I.

• First principles modeling– detailed flow field– catalyst surface morphology– gas-surface reactions (morphology

dependence)– unsteady dynamics both flow and reactive– mathematics for sensitivity analysis

Non Proprietary Needs II.

• Measurement verification of simulations– detailed flow field– catalyst surface morphology– gas-surface reactions (morphology

dependence)– unsteady dynamics both flow and reactive– to be determined needs

Multidisciplinary Projects Can Provide Multidisciplinary Projects Can Provide Faster Track to Improved CatalystsFaster Track to Improved Catalysts

Microscale(thermal & chemical)-Coupled reaction lattices-Pore/surface diffusion-Adsorption/storage

Macroscale(Overall emissions)-Exhaust/inlet CFD-Homogeneous reaction-Coupled w engine

Mesoscale(Smallest continuum)-Stiff nonlinear PDEs-Ignition/extinction waves

ModelingModeling ExperimentalExperimentalMicroscopic

Characterization-TEM, X-ray diffraction, etc.-Micro transport parameters

Ideal Flow Studies-Single wafer (boundary layer)-Channel flow (brick section)-Limited transients

-Test stand-Vehicle testing-Realistic transients

Engine Studies

Technical Workshops

• Overall Concept– Promote research collaborations in emission controls simulation– Identify state-of-the-art for various technologies and models– Identify key unresolved issues, technical paths to solutions

• Approach– Sponsor workshops focused on specific simulation topics– Workshop parameters

• 2 days each, 3/yr at accessible locations (e.g., Detroit, Chicago)• Participation by industry, academia, national labs• Specific topic, 3-4 invited talks, 8-10 contributed talks• Published proceedings (Website)

What do we want from this workshop?

•Introduce the program

–What, where, when and how

•Bring the players together

•Get feedback on the direction of the program

– Especially the common computing environment

•Get feedback on technical priorities

–Tuesday afternoon prioritization will direct future technical meetings and help define the structure of the center

Wrap-Up• This program:

– could be the common ground for math based emission system development (code formats, types of applications….)

– provides an environment for future R & D onemissions simulation (technical meetings and collaborations)

– could define industry wide standards for interchangeable simulations modules (participation by the catalyst manufacturers may standardize “new catalyst” simulation modules)

Website

• General Approach– Construct and maintain a website at ORNL

through which external users can meet previous objectives

– Provide tutorial and education– Institute security controls to limit access

according to the users (e.g., public, crosscut member, proprietary)

Website• Objectives

– Encourage information transfer, collaboration– Interface for crosscut members to access

simulation framework, benchmark case parameters, benchmark results

– Access to publicly shared component codes– Workshop announcements, distribution of

proceedings– On-line discussions– Posting of important research results– Possible access to advanced DOE computing

resources for industry, universities

Website Implementation of Shared Simulation Environment

MATLAB or GT Power

Aftertreatment System Modeling

• Gives transparent access to heterogeneous distributed resources

• Supports new component creation and use• Seamlessly incorporates new hardware and

software

Support prediction, analysis, and collaboration in an integrated web-accessibleenvironment that:

Problem-Solving Environment

Example Website: www.ornl.gov/doe2k/html

DeepView: Remote access to microscope images and controls

The Full System Modeling Vision

Flex Coupling

GoalDevelop a Full System Modeling Framework with Defined, FlexibleInterfaces that can Accommodate Various Component Sub-Models

Intake, Combustion & Emissions Model

Exh. Manifold Mode1

#1 Catalyst or Device Mode1

Pipe

Brick 1, 2, . .• Volume, Surface Area • PGM Loading• Flow Distribution- CFD • Substrate Properties• Chemical Reactions• Aging, Poisoning• Etc

• Material Properties• Dimensions• Flow Distribution -CFD • Wall Thickness• Smoothness ( Chuff )• Etc

# 1 Pipe Mode1

• Exhaust Flow • Air-Fuel Ratio• Temperature• HC & NOx Species• CO, CO2, etc• Gas Phase Reactions• Etc

Engine-Out Data

Flex Coupling

Pipe

Heat & Species Input

From Air Intake to Tailpipe Exhaust

#2 Catalyst or Device Mode1

# 2 Pipe Mode1